Fabrication Of Zsm-5Zeolites With Ordered Mesoporous-microporous Hierarchical Structure For Benzene And Ethanol Alkylation

In the petroleum chemical industry, Ethylbenzene (EB) is an importantintermediate in the petrochemical industry for the production of styrene andpolystyrene. The traditional method in the synthesis of EB is benzene alkylation withethene on Friedel-Crafts catalysts. the vapor phase ethylation of benzene withethanol by using ZSM-5zeolites as catalysts has attracted many interests in theproduction of EB. In this paper, we use ethanol as an alkylating agent over ZSM-5zeolites, Synthesis of ordered mesoporous ZSM-5zeotilites according to the followingstages:first synthesis of MCM-41microspheres by using organic templatemethod;then hydrothermal transformation of MCM-41to ZSM-5zeolites viadissolution-precipitation reation. At last, ordered mesporous ZSM-5zeolites can beobtain after calcination.The second chapter in this paper, we study temperature on the MCM-41morphology, and focus on the exploration from the thermodynamic temperature onthe MCM-41and the influence of the formation mechanism. Via XRD, FT-IR, FESEM,BET, we can test temperature on the formation of MCM-and the influence of themechanism. In chapter3, Factors affecting the synthesis of ZSM-5zeolites werestudied, including PH values crystallization time and temperature, So the bettercrystallization and order condition wasPH=7.5, crystallization time of7days andtemperature of140℃. In Chapter4, we investigate different Si/Al ratio on particlessize、crystalline. The crystalline increased with the increase of Si/Al ratio, but thecatalytic activity decreased.In Chapter5, the performances of all the as-synthesized samples had beeninvestigated in the alkylation of benzene and ethanol. The sample with Si/Alratio、crystallization time of7days and temperature of140℃has highercrystallinity,larger surface area, more acid sits, so the catalyst shows better catalytic: the single pass conversion of ethanol、benzene and the selectivity of ethylbenzene(SEB%) were（28.4±2.0）%、（62.2±1.2）%and（83.6±2.2）%. With the increaseof Si/Al ratio, the catalytic activity decreased. When the Si/Al ratio reach to200, theselectivity of ethylbenzene (SEB%) decreaced to（69.6±1.9）%.